1. Field of the Invention
The invention relates to a folding roof for a convertible, with a canvas top which is held by a top frame, which frame has side roof rods, a main bow and a top mechanism supported on the body for opening and closing the folding roof, which contains a side main column, one end of which is pivotally mounted on the body and the other in a pivot joint on the roof rod and is adjoined by the canvas top which is tensioned when the top is closed.
2. Description of the Related Art
In a known folding roof of the above mentioned type, the main bow is permanently joined to the main column and is entrained with it when the folding roof is lowered into the rear storage space without relative movement to the main column. The canvas top attached to the main column and also to the main bow can thus be lowered without overstretching. Instead of a fixed attachment of the canvas top to the main column, or in a top frame construction with relative movement between the main bow and the main column during lowering, there can also be a wire cable which presses the canvas top against the main column for tensioning.
A primary object of the present invention is to devise a folding roof the initially mentioned type which has a canvas top which is protected against overstretching by the components which hold the canvas folding roof, even in folding roof frame structures which experience relative movement between the main bow and the main column when the roof is lowered into a rear storage space.
This object is achieved in accordance with the invention by the main bow forming a roof cassette which is permanently connected to the roof rod and by an additional rod being movably arranged in the area of the main column and being kinematically coupled to a component, especially a folding roof frame part or a body-mounted part, to which the additional rod executes relative motion when the main column executes a pivoting motion, the canvas top adjoining or being attached to the additional rod and the additional rod executing motion controlled by the component for relieving or tensioning of the canvas folding roof during pivoting motion of the main column relative to the roof cassette during opening and closing of the folding roof. The specifically movable additional rod can thus relieve the canvas top which can follow the roof cassette which continues to move during pivoting, by which overstretching of the canvas top is prevented. The roof rod which is permanently connected to the roof cassette can thus be a short, rear roof rod to which a front roof rod is pivotally coupled, or a side bearing component of the roof cassette.
When the component which is kinematically coupled to the additional rod is the roof cassette, a coupling can be established with a simple connection to this part, which is important for tensioning the folding roof. In one practical embodiment, in this case, the additional rod is movably supported on the main column, the canvas top is attached to the additional rod and a coupling means joins the additional rod to the roof cassette so that, in the pivoting motion of the main column relative to the roof cassette, the additional rod remains within a fixed distance to the coupling point of the coupling means on the roof cassette.
The coupling means can have different connecting elements, for example, rod levers or Bowden cables, but advantageously, also contains a coupling rod which is pivot mounted by a joint on the roof cassette and by a joint on the additional rod.
In another embodiment, the component which is kinematically coupled to the additional rod is a body-mounted part, especially a main bearing which is attached to the body for the pivoting main column. Thus, the relative motion of the main column to the body is used directly or via interposed gearing to control the motion of the additional rod. In one practical embodiment the additional rod is movably supported on the main column, the canvas top is attached to the additional rod, and a coupling means connects the additional rod to the body-mounted part, especially the main bearing, so that, in the pivoting motion of the main column relative to the roof cassette and to the body-mounted part, the additional rod remains within a fixed distance of the coupling point of the coupling means on the body-mounted part, especially the main bearing, and thus, also to the roof cassette.
Another advantageous embodiment calls for a telescoping additional rod arrangement, in which the additional rod is pivotally coupled to the body-mounted part, especially the main bearing, is guided to be able to move lengthwise on a guide element which is pivot mounted on the roof cassette, and in the pivoting motion of the main column, executes a relative displacement motion with respect to this guide element. The guide element can be, for example, a seal carrier to which a seal for the back section of a side window is attached. The additional rod as well as the seal carrier can be made as elongated, identically curved elements.
Another embodiment calls for the component which is kinematically coupled to the additional rod to be a section of the canvas top which is attached to the body. The canvas top which is attached to the equator of the body in this case represents the transfer of motion to the additional rod.
An advantageous embodiment of the top frame calls for the top mechanism to contain, on each side, a parallelogram-like four-bar mechanism with the main column and the main connecting rod which are pivot mounted at one end to the body and the other to a bearing component of the roof cassette. Thus, the roof cassette is easily pivoted rearward into the storage position in a largely horizontal alignment. However, also other mechanisms, such as gears or the like, can be used for the controlled pivoting motion of the roof cassette on the main column.
According to one advantageous embodiment, if the side roof rods are each divided into a front and a rear roof rod which, in the closed position of the folding roof, form an essentially rigid top frame which is releasably coupled to the front transverse frame, the coupling being released in the storage position of the opened canvas folding roof so as to be housed in a compact arrangement, and the roof cassette is securely attached to the rear roof rod, for example, by a pivot joint connection, the roof rod which is the front can be pivoted, one at a time, relative to the rear roof rod and when the folding roof is lowered can be located parallel to the main bow.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.